Need help with adding various colors to BMP File

Ok, so I have a program that essentially takes in a bmp file, and outputs a output bmp. Now, if I did nothing to the input file, then essentially the same file will write as the output file. I have the capability of altering the color of the out file to a single color.But for the life of me,I cant figure out how to add multiples color to the output file. So say for example, if I had a input file that contains the colors red and white. How would I alter it(the input file) to change the color format to say, blue and white. Here is the code I have:

Code:

   for (int j = 0; j < bi.biWidth; j++)
        {
            // temporary storage
          RGBTRIPLE triple;// RGBTRIPLE is a struct 
          BYTE temp; //BYTE is a struct that is made up of uint8_t.
           
             char temp2[7]="ff";
         
            
            fread(&triple, sizeof(RGBTRIPLE), 1, inptr);
          
           
             temp= (BYTE)temp2; 
             triple.rgbtGreen=temp;
             triple.rgbtRed=temp;
             triple.rgbtBlue=00;
           
           
            fwrite(&triple, sizeof(RGBTRIPLE), 1,outptr);
           
        }

Any help would be greatly apprecitaed. Thanks.

Perhaps
triple.rgbtGreen=0xff;
triple.rgbtRed=0xff;
triple.rgbtBlue=0x00;

Instead of all that mucking about with strings.

I see. But what if I want the file to have a mixture of white included with that yellow. How would I go about implementing that.

You could use one of the many HTML color charts, for example

HTML Color Chart

Look at the hex codes in the HTML color you like and use those values as your red, green, and blue parts

Originally Posted by c99tutorial

You could use one of the many HTML color charts, for example

HTML Color Chart

Look at the hex codes in the HTML color you like and use those values as your red, green, and blue parts

Cool. So with my code, if I wanted to generate a mixture of white and red, I would just pick a color that does that for me? When glancing at a scanline of pixels on a bmp, I see both red and white hex codes being used. How is that implemented?

Pick a colour
Say
Deepskyblue #00BFFF

Take the appropriate pair of hexadecimal digits.
Put 0x in front of them in your C code.
Assign the appropriate members of your colour triple struct.

got it, thank you!